I have to build a program that has a menu-driven program that has a user input the selection he/she wants and loops until the user types 'q'. This program does not end like it is supposed to when I type in the selction of 'q'. Instead it says 'Incorrect choice, please enter a new selection' when it should be ending. I had to make the program so that it would catch incorrect characters, but I need it to recognize 'q' as my sentinel value so it will end. Any suggestions are appreciated. Thank you.
CODE
/*prototype Math Calculator*/
#include <stdio.h>
int calculate_sum(x, y){ /*function to calculate sum of two integers*/
int sum = x + y; /*equation*/
return sum; /*the sum of x,y*/
} /*end function*/
int calculate_difference (x, y){/*function to calculate distance of two integers*/
int difference = x - y; /*equation*/
return difference; /*difference of x,y*/
}/*end function*/
int calculate_product (x, y){/*calculate product of two integers*/
int product = x * y; /*equation*/
return product; /*returns the product of x,y*/
} /*end function*/
float calculate_quotient (int x, int y){ /*calculates the quotient of two values*/
while (y == 0) {
printf ("Sorry, you cannot divide by 0, enter a new menu selection\n\n");
} /*end while*/
if ( y != 0){ /*begin if statement*/
int quotient = x / y;
return quotient;
} /*end if*/
}/*end function calculate_quotient*/
int calculate_intPower (x, y){/*function to calculate base to power exponent*/
int intPow = 1;/*initialize variable intPow*/
int i; /*initialize i*/
if (y <1){ /*begin if*/
return 1;
}/*end if*/
for ( i = 1; i <= y; ++i ) {
intPow = intPow * x;
}/*end for*/
return intPow;
}/*end function intPower*/
float calculate_gcd (int x, int y){/*function to calculate GCD*/
if (x < y){ /*begin if*/
int swap(x,y);
} /*end if*/
while (y != 0) {
int remainder = x % y;
x = y;
y = remainder;
return x;
} /*end while*/
}/*end function*/
int calculate_factorial (int x){ /*calculate factorial of an integer*/
int factorial = 1; /*initialzie variable*/
int counter = 0; /*initialzie variable*/
if ( x <= 1) {/*begin if*/
return 1;
}/*end if*/
for ( counter = x; counter >= 1; counter -- ){/*begin for*/
factorial *= counter;
}/*end for*/
return factorial;
}/*end funtion calculate_factorial*/
int main ()/*begin main function*/
{
int user_choice;
int x;
int y;
int q = 0;
printf ("Welcome to the Super Math Calculator!!!");
printf ( "\n\nPlease select one of the following menu items");
printf ( "\n\n1. Add two integers");
printf ( "\n2. Subtract two integers" );
printf ( "\n3. Multiply two integers" );
printf ( "\n4. Divide two integers" );
printf ( "\n5. Calculate an integer raised to a positive integer power" );
printf("\n6. Compute the Greatest Common Divisor of two integers" );
printf ( "\n7. Compute the factorial of an integer" );
printf ( "\nq. Quit\n\n" );
/*loop until user types “q”*/
while ( (user_choice = getchar() ), user_choice != q ){
/*determine which choice was input*/
switch (user_choice) {
case '1':
printf ( "\nEnter the first integer to add:" );
scanf ( "%d", &x );
printf ( "\nEnter the second integer to add:" );
scanf ( "%d", &y);
printf ("\nThe sum of %d and %d is %d\n\n", x,y, calculate_sum(x,y) );
break; /*exit switch*/
case '2':
printf ( "\nEnter the first integer to subtract:" );
scanf ( "%d", &x );
printf ( "\nEnter the second integer to subtract:" );
scanf ( "%d", &y);
printf ("\nThe difference of %d and %d is %d\n\n", x,y, calculate_difference(x,y) );
break; /*exit switch*/
case '3':
printf ( "\nEnter the first integer to multiply:" );
scanf ( "%d", &x );
printf ( "\nEnter the second integer to multiply:" );
scanf ( "%d", &y);
printf ("\nThe product of %d and %d is %d\n\n", x,y, calculate_product(x,y) );
break; /*exit switch*/
case '4':
printf ( "\nEnter the first integer to divide:" );
scanf ( "%d", &x );
printf ( "\nEnter the second integer to divide by:" );
scanf ( "%d", &y);
printf ("\nThe quotient of %d and %d is %.2f\n\n", x,y, calculate_quotient(x,y) );
break; /*exit switch*/
case '5':
printf ( "\nEnter the first integer base:" );
scanf ( "%d", &x );
printf ( "\nEnter the second integer exponent:" );
scanf ( "%d", &y);
printf ("\n%d to the %d power is %d\n\n", x,y, calculate_intPower(x,y) );
break; /*exit switch*/
case '6':
printf ( "\nEnter the first integer:" );
scanf ( "%d", &x );
printf ( "\nEnter the second integer t:" );
scanf ( "%d", &y);
printf ("\nThe Greatest Common Denominator of %d and %d is %d\n\n", x,y, calculate_gcd(x,y) );
break; /*exit switch*/
case '7':
printf ( "\nEnter an integer:" );
scanf ( "%d", &x );
printf ("\nThe factorial of %d is %.2f\n\n", x, calculate_factorial(x) );
break; /*exit switch*/
case '\n':
case '\t':
case ' ':
break; /*exit switch*/
default: /*catch all other characters*/
printf ( "Incorrect choice, enter a new selection!\n\n");
break; /*exit switch*/
} /*end switch*/
} /*end while*/
printf ( "Thank you for using the Super Math Calculator\n\n" );
return 0;
}
7 Oct, 2008 - 02:21 PM
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